Re: ASM on SAN

From: LS Cheng <exriscer@xxxxxxxxx>

To: cshapi@xxxxxxxxx

Date: Mon, 22 Feb 2010 09:22:13 +0100

Use option 1, if you have redundancy in SAN then there is no point to use
ASM mirroring. I have only used ASM redundancy once in a JBOD storage array
and many times for extended clusters.
Use multiple LUNs since there are some parameters (at leats in Solaris)
which can limit number of I/O requests to a LUN so if you have few LUNs you
are actually lowering your S.O I/O throughput. Also as others already
pointed out if you use a large LUN and you plan to follow ASM best practice
then each time you want to grow you are increasing your ASM Disk Group size
by two which can be a waste of space. I have implemented in a few customer
two standard LUN sizes for small/middle and large databases.
Thanks
--
LSC
On Sun, Feb 21, 2010 at 8:16 PM, Chen Shapira <cshapi@xxxxxxxxx> wrote:
> Hi Oracle-L,
>
> I'm preparing to install ASM using our EVA storage and I'm trying to
> decide how many volumes to request from my storage manager.
>
> There are two configurations we consider:
> 1) Ask for two volumes - one for data files, the other for flashback,
> archive logs, backups, etc. Then run ASM with external redundancy and
> external striping. Let EVA do the RAID thing for us.
> 2) Ask for multiple data volumes and multiple backup volumes.
> Configure ASM to do its own striping. Since EVA will do its own
> stripe+mirror thing, we'll have double striping.
>
> I'm leaning toward the first option since it seems more manageable.
>
> Does anyone on the least have a good reason to go with the second
> option? I'm worried that I'm missing something, because all ASM papers
> natually assume there will be multiple ASK "disks".
>
> Chen
> --
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>
>
>